Agitator Basics

What are agitators? Agitators are devices that are used to stir or mix fluids, especially liquids, which is one of the basic mechanical process engineering operations. Essentially, agitators are used for the homogenization of liquids or liquid-solid mixtures by generating horizontal and vertical flows. These flows are generated by rotating agitator blades.

The Agitator Process

A rotating agitator generates high speed streams of liquid which in turn entrain stagnant or slower moving regions of liquid resulting in uniform mixing by momentum transfer. When it is necessary to mix materials of different densities, it is better to use vertical flow agitators because of the tendency of sedimentation of the denser component. Wherever possible, movement of the entire amount of material together in the mixing vessel, which occurs frequently during the agitation process, should be avoided because of the unwanted separation caused by centrifugal forces.

At the simplest level, agitators consist of an impeller and a shaft. An impeller is a rotor inside a tube or conduit attached to the shaft. It is used to increase the pressure and flow of a fluid. Modern agitators use sophisticated process control electronic devices to regulate the mixing process.

Agitators are typically used in…

Chemical Process Industry: The chemical industry uses agitators extensively for mixing and blending of various chemicals.

Food industry: Preparation of cake mix, spices, and flavors

Paint Industry: Agitators are used to mix liquid-liquid and liquid-solid raw material properly

Pharmaceutical Industry: Blending of active ingredients of a formulation